My speculation is that after the ending of Resurrection, Gabriel will still be changing in to his final form (which would more than likely happen after a few levels in game) and we will see him clear out house and eventually gain mastery and dominance over the demon castle, thus becoming its true master. Since we had seen the Devil's Mask fused with him in the game's original ending.
So apparently the castle is a lot larger from earlier interviews. So it is more than speculated that there will be a SoTN like feel to it. I'm also guessing is that it will take place back in that time frame or present time (depending on how they feel since he technically traveled back in time.) But I am assuming that the Lords of Shadows are still alive during this reign.
So he has all three powers of the dark lord, he has become the Prince of Darkness, but has yet to fuse with the Devil's Mask. So I'm kinda eager to see how well Cox's vision of Castlevania will play out, as I think it will be interesting to play as the D man himself instead of some boring (no offense; I thought he was a good character) reincarnation of the man.